In vertical shaft centrifugal impact crushing machines, bulk particulate material is fed centrally onto a horizontal turntable. The turntable is rotated about a vertical axis at high speed. Impeller shoes are mounted on the turntable to engage and thrust the particulate material at high velocity radially outward from the central portion of the turntable. The outwardly moving particles impact against stationary-wear resistant anvil members positioned about the periphery of the turntable. When the material strikes the anvil members, instantaneous deceleration forces cause the material to break into smaller pieces.
The impellers are subject to considerable wear due to the constant frictional engagement with the particles. They are therefore preferably made to be easily removed from the turntable. Upright brackets are typically provided to releasably mount the impeller shoes at equal angular locations about the turntable. The brackets must be rigidly fixed to the turntable in order to withstand centrifugal forces applied by the impeller shoes and by the particulate material impacting against the shoes. The brackets are therefore difficult to remove from the turntable.
Material leaving the turntable to engage the impact shoes does not always strike the shoes first. Some particles will inevitably strike against the brackets. The brackets experience wear along with the impeller shoes. It is desirable to provide some form of bracket that can be protected against excessive wear.
One of the principal purposes of this invention is to provide a shoe bracket assembly with a greatly increased useful life.
A further object is to provide a shoe bracket in which the areas susceptible to wear are removable, thereby avoiding the necessity of periodically removing the entire shoe bracket assembly for replacement.
These and other objects and advantages of this invention will become apparent upon reading the following detailed description of a preferred embodiment.